Rethinking Ketchup Packets: New Approach to Slippery Packaging Aims to Cut Food Waste

Benefits Also Include Consumer Safety and Comfort

Date: August 3, 2018
Source: Virginia Tech
Summary: New research aims to cut down on waste -- and consumer frustration -- with a novel approach to creating super slippery industrial packaging. The study establishes a method for wicking chemically compatible vegetable oils into the surfaces of common extruded plastics, like those used for ketchup packets and other condiments.

Virginia Tech doctoral student Ranit Mukherjee observes a dollop of ketchup as it moves on a super slippery plastic film. Mukherjee is the lead author on a study that yielded a novel approach to creating super slippery industrial packaging.
Credit: Virginia Tech

Almost everyone who eats fast food is familiar with the frustration of trying to squeeze every last drop of ketchup out of the small packets that accompany french fries.

What most consumers don't realize, however, is that food left behind in plastic packaging is not simply a nuisance. It also contributes to the millions of pounds of perfectly edible food that Americans throw out every year. These small, incremental amounts of sticky foods like condiments, dairy products, beverages, and some meat products that remain trapped in their packaging can add up to big numbers over time, even for a single household.

New research from Virginia Tech aims to cut down on that waste -- and consumer frustration -- with a novel approach to creating super slippery industrial packaging.

The study, which was published in Scientific Reports and has yielded a provisional patent, establishes a method for wicking chemically compatible vegetable oils into the surfaces of common extruded plastics.

Not only will the technique help sticky foods release from their packaging much more easily, but for the first time, it can also be applied to inexpensive and readily available plastics such as polyethylene and polypropylene.

These hydrocarbon-based polymers make up 55 percent of the total demand for plastics in the world today, meaning potential applications for the research stretch far beyond just ketchup packets. They're also among the easiest plastics to recycle.

"Previous SLIPS, or slippery liquid-infused porous surfaces, have been made using silicon- or fluorine-based polymers, which are very expensive," said Ranit Mukherjee, a doctoral student in the Department of Biomedical Engineering and Mechanics within the College of Engineering and the study's lead author. "But we can make our SLIPS out of these hydrocarbon-based polymers, which are widely applicable to everyday packaged products."

First created by Harvard University researchers in 2011, SLIPS are porous surfaces or absorbent polymers that can hold a chemically compatible oil within their surfaces via the process of wicking. These surfaces are not only very slippery, but they're also self-cleaning, self-healing, and more durable than traditional superhydrophobic surfaces.

In order for SLIPS to hold these oils, the surfaces must have some sort of nano- or micro-roughness, which keeps the oil in place by way of surface tension. This roughness can be achieved two ways: the surface material is roughened with a type of applied coating, or the surface material consists of an absorbent polymer. In the latter case, the molecular structure of the material itself exhibits the necessary nano-roughness.

Both techniques have recently gained traction with startups and in limited commercial applications. But current SLIPS that use silicone- and fluorine-based absorbent polymers aren't attractive for industrial applications due to their high cost, while the method of adding roughness to surfaces can likewise be an expensive and complicated process.

"We had two big breakthroughs," said Jonathan Boreyko, an assistant professor of biomedical engineering and mechanics and a study co-author. "Not only are we using these hydrocarbon-based polymers that are cheap and in high demand, but we don't have to add any surface roughness, either. We actually found oils that are naturally compatible with the plastics, so these oils are wicking into the plastic itself, not into a roughness we have to apply."

In addition to minimizing food waste, Boreyko cited other benefits to the improved design, including consumer safety and comfort.

"We're not adding any mystery nanoparticles to the surfaces of these plastics that could make people uncomfortable," he said. "We use natural oils like cottonseed oil, so there are no health concerns whatsoever. There's no fancy recipe required."

While the method has obvious implications for industrial food and product packaging, it could also find widespread use in the pharmaceutical industry. The oil-infused plastic surfaces are naturally anti-fouling, meaning they resist bacterial adhesion and growth.

Although the technique may sound very high-tech, it actually finds its roots in the pitcher plant, a carnivorous plant that entices insects to the edge of a deep cavity filled with nectar and digestive enzymes. The leaves that form the plant's eponymous shape have a slippery ring, created by a secreted liquid, around the periphery of the cavity. When the insects move onto this slippery ring, they slide into the belly of the plants.

"This slippery periphery on the pitcher plant actually inspired our SLIPS product," said Mukherjee.

The pitcher plant's innovation -- which engineers are now copying with great success -- is the combination of a lubricant with some type of surface roughness that can lock that lubricant into place very stably with surface tension.

"We're taking that same concept, but the roughness we're using is just a common attribute of everyday plastics, which means maximal practicality," said Boreyko.

This research was funded through an industrial collaboration with Bemis North America. Additional co-authors of the study include Mohammad Habibi, a Virginia Tech mechanical engineering graduate student; Ziad Rashed, an engineering science and mechanics 2018 graduate from Virginia Tech's undergraduate program; and Otacilio Berbert and Xiangke Shi, both of Bemis North America.



Reprinted From:
Virginia Tech. "Rethinking ketchup packets: New approach to slippery packaging aims to cut food waste: Benefits also include consumer safety and comfort." ScienceDaily. ScienceDaily, 3 August 2018. https://www.sciencedaily.com/releases/2018/08/180803103302.htm

Small Amounts of Pharmaceuticals Found in North Central Pa. Rural Well Water

Date: July 31, 2018
Source: Penn State
Summary: Drinking water from wells in rural north central Pennsylvania had low levels of pharmaceuticals, according to a new study.

While septic tanks are generally installed downgradient of wells, contaminant from septic systems can impact well water quality, especially if the septic systems are not maintained or were improperly installed. Pharmaceuticals that are incompletely degraded in septic tanks and leaching fields can travel with wastewater and infiltrate groundwater.
Credit: Heather Gall Research Group / Penn State

Drinking water from wells in rural north central Pennsylvania had low levels of pharmaceuticals, according to a study led by Penn State researchers.

Partnering with volunteers in the University's Pennsylvania Master Well Owner Network, researchers tested water samples from 26 households with private wells in nine counties in the basin of the West Branch of the Susquehanna River. All samples were analyzed for seven over-the-counter and prescription pharmaceuticals: acetaminophen, ampicillin, caffeine, naproxen, ofloxacin, sulfamethoxazole and trimethoprim.

At least one compound was detected at all sites. Ofloxacin and sulfamethoxazole -- antibiotics prescribed for the treatment of a number of bacterial infections -- were the most frequently detected compounds. Caffeine was detected in approximately half of the samples, while naproxen -- an anti-inflammatory drug used for the management of pain, fever and inflammation -- was not detected in any samples.

"It is now widely known that over-the-counter and prescription medications are routinely present at detectable levels in surface and groundwater bodies," said Heather Gall, assistant professor of agricultural and biological engineering, whose research group in the Penn State's College of Agricultural Sciences conducted the study. "The presence of these emerging contaminants has raised both environmental and public health concerns, particularly when these water supplies are used as drinking water sources."

The good news, Gall pointed out, is that the concentrations of the pharmaceuticals in groundwater sampled were extremely low -- at parts per billion levels. However, given that sampling with the Master Well Owner Network only occurred once, the frequency of occurrence, range of concentrations and potential health risks are not yet well understood, especially for these private groundwater supplies.

The researchers used a simple modeling approach based on the pharmaceuticals' physicochemical parameters -- degradation rates and sorption factors -- to provide insight into the differences in frequency of detection for the target pharmaceuticals, noted lead researcher Faith Kibuye, who will graduate with a doctoral degree in biorenewable systems next year.

She explained that calculations revealed that none of the concentrations observed in the groundwater wells posed any significant human health risk, with risk quotients that are well below the minimal value. However, the risk assessment does not address the potential effect of exposure to mixtures of pharmaceuticals that are likely present in water simultaneously, she said. For example, as many as six of the analyzed pharmaceuticals were detected in some groundwater samples.

"There remains a major concern that even at low concentrations, pharmaceuticals could interact together and influence the biochemical functioning of the human body, so even at very low concentrations they might have some kind of synergistic effect," Kibuye said. "We only analyzed for seven pharmaceuticals but the chances are that there may have been many more."

The findings of the research -- which Kibuye will present today (July 31) at the annual meeting of the American Association of Agricultural and Biological Engineers in Detroit -- should be of interest the world over because groundwater is a critical supply of drinking water globally.

It is estimated that half of the population accesses potable water from groundwater aquifers. In the United States, approximately 13 million households use private wells as their drinking water source, according to the U.S. Environmental Protection Agency. In Pennsylvania, approximately one-third of the residents receive their drinking water from private groundwater wells, Penn State Extension surveys show.

It is common for homeowners with private wells to also have septic tanks on their properties for treatment of their wastewater. And while septic tanks are generally installed downgradient of the well, it is possible that contaminant from septic systems can impact well-water quality, especially if the septic systems are not maintained or were improperly installed.

"While common contaminant issues include fecal coliform, E. coli and nitrate, pharmaceuticals and other compounds of emerging concern pose potential threats to well water quality," Kibuye said. "Pharmaceuticals that are incompletely degraded in septic tanks and leaching fields can therefore travel with wastewater plumes and impact groundwater, potentially making septic systems important point sources to surrounding domestic groundwater sources."

Story Source:

Penn State. "Small amounts of pharmaceuticals found in north central Pa. rural well water." ScienceDaily. ScienceDaily, 31 July 2018. https://www.sciencedaily.com/releases/2018/07/180731141630.htm